I too experimented and got to where I used IAS 290 until the climb rate dropped below 1000fpm, then climbed in VS mode at 1000fpm to cruise altitude. Normally the IAS would be around 260-270 when you leveled off if you were going FL300-340, and I never saw lower than 250kts. I found it got you to altitude in a reasonable amount of time and still with enough airspeed on the wing to allow acceleration to .74M or higher under all conditions (well, without cowls anyway).